This Guggenheim show focuses on the early works of the seminal Abstract Expressionist painter Robert Motherwell, specifically in the kid-friendly medium he once called “the greatest of our [art] discoveries”: collage. It looks at the young artist’s style and the significance of collage in his lifelong oeuvre, as well as the ways in which he broke ground with the medium’s techniques. The works’ geometric, abstract shapes and layers are never boring, thanks to ink drawings that pop, gouache passages that float and anthropomorphic elements with a joy-exuding, childlike simplicity. All ages.